Basic Information

All right. So that isn't particularly helpful. A better distinction would be to say that a disciple is a student and an apostle is a teacher. The word comes from the Greek apostolos, meaning one sent forth as a messenger. (The Latin version of the term, missio, is where we get the word "missionary". I didn't know that.).

The name "Apostle" is given to the Twelve Disciples of Jesus. He had many other disciples, but the Gospels record him choosing twelve of them to be his closest companions. Very likely he chose the number twelve to match the Twelve Tribes of Israel. According to the Gospel of Mark, the Twelve Disciples were:

Peter, originally known as Simon

Andrew, brother of Peter

James, the son of Zebedee

John, the brother of James

Philip

Bartholomew

Matthew, the tax collector; also called Levi

Thomas, also called Didymus, or "the Twin"

James, son of Alpheus, sometimes called "James the Less"

Thaddeus

Simon the Zealot

Judas Iscariot

The Gospel of Matthew follows the listing given in Mark. Luke gives a similar list, but lists Judas, the son of James in place of Thaddeus and refers to Simon the Zealot as Simon the Canaanite. John does not give a complete list of all twelve.

In addition, other people were referred to as Apostles. After the death of Judas, the remaining Disciples chose Matthias to take his place so that there would be an even dozen. Paul claimed to be an apostle by virtue of having witnessed the risen Christ; (presumably a reference to his Conversion). Apparently some people were making snarky comments that he wasn't a "real" apostle, because he gets quite defensive about it. Paul refers to other people in his letters as "apostles", including Barnabas, Silas, Timothy, and most controversially, a woman named Junia (Romans 16:7). Some translations change her name to "Junias" to make the name sound less feminine.

See Also

Calendar of Saints — a list of prominent Apostles and the dates set aside by the church to commemorate them.

Sources

Game and Story Use

A time travel or historical campaign could include an encounter with one or more apostles, either members of The Twelve, or possibly other less famous apostles.

The GM should be careful to consider how his group feels about blasphemy

If the GM is particularly daring, he can let a PC be an Apostle. Just don't let the Pope find out.

Historically, things that came in groups of a dozen or so often got named as/after Apostles - from the black powder flasks carried by some early musketeers to a class of Spanish Galleons (several of which were memorably engaged - and a few of them lost - fighting Sir Richard Grenville at the Azores).